Initial Density Difference Research Articles

Assessing the Damage caused by Heterodera rostochiensis Woll.

PREVIOUSLY there have been no published accounts of the effect of any species of Heterodera on the yield of the host crop under field conditions. Jones1 attempted to obtain conditions approaching those found in the field by the use of small, artificially constructed plots or microplots. However, these were too small to give a realistic estimate of yield per acre. For insect pests differential population density-levels have been established by the use of insecticides. This is impractical, for eelworms as nematicides, in addition to affecting the eelworm population, also often exert an effect on plant growth. I have therefore investigated the effect on the yield of potatoes of differences in initial density of eelworm population. This method, possibly with some modification, should prove suitable for other Heterodera species or for any species of nematode for which reliable population estimates can be made.

Jet Diffusion in Liquid of Greater Density

Investigations show how density and velocity along axis of jet depend on initial density difference between jet and surrounding fluid and on velocity of jet when it issues from nozzle; description of experimental setup; results apply to case of sewage disposal in marine environment.

Jet Diffusion in Liquid of Greater Density

Investigations show how density and velocity along axis of jet depend on initial density difference between jet and surrounding fluid and on velocity of jet when it issues from nozzle; description of experimental setup; results apply to case of sewage disposal in marine environment.